Signalling coding and modulation method and demodulation and decoding method and device

ABSTRACT

Provided are a signaling coding and modulation method and a demodulation and decoding method and device, characterized in that the method comprises the steps of: extending signaling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword; conducting parity bit permutation on a parity bit portion in the encoded codeword and then splicing the permutated parity bits to the end of information bits in the encoded codeword, to obtain a permutated encoded codeword; according to the length of the signaling, punching the permutated encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence, which is used for mapping, and then mapping the tuple sequence.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. patent application Ser. No. 16/748,739 filed Jan. 21, 2020, which is a continuation application of U.S. patent application Ser. No. 15/558,184 filed Sep. 13, 2017 and issued Mar. 17, 2020 with U.S. Pat. No. 10,594,435, which is a national phase entry under 35 USC § 371 of International Application PCT/CN2016/076129, filed Mar. 11, 2016, which claims priority to and benefits of Chinese Patent Applications Serial No. 201510111992.X filed with the State Intellectual Property Office of P. R. China on Mar. 13, 2015, and Chinese Patent Applications Serial No. 201510125240.9 filed with the State Intellectual Property Office of P. R. China on Mar. 20, 2015, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the technical field of digital televisions, and in particular to a signalling coding and modulation method and a demodulation and decoding method and device.

BACKGROUND

In the existing broadcast communication standards, such as a DVB-T2 system, every physical frame contains signalling and data, wherein the signalling indicates information such as coding and modulation, an interleaving mode, etc. of each service contained in the data. A receiving threshold of the signalling must be lower than a receiving threshold of all the services contained in the data in the physical frame. Therefore, coding and modulation of the signalling should provide stronger protection than the data, and at the same time should also provide a spectrum frequency as high as possible. In addition, the length of the signalling is variable with regard to each physical frame, and therefore coding and modulation of the signalling must also provide corresponding flexibility.

With the emergence of services of a large data volume such as ultra HD, etc., receiving thresholds of some services are also improved. The receiving thresholds of some services in a white noise channel have exceeded 25 dB or even 30 dB, then the existing technology is hard to provide a signalling coding and modulation and demodulation and decoding method which requires high efficiency and flexibility.

SUMMARY

The objective of the present invention is to provide a corresponding high-efficient and flexible signalling coding and modulation method and a demodulation and decoding method and device for a service with a relatively high receiving threshold.

In order to solve the above problem, an embodiment of the present invention provides a signalling coding and modulation method, characterized in that the method comprises the steps of: extending signalling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword; conducting parity bit permutation on a parity bit portion in the encoded codeword and then splicing the permutated parity bits to the end of information bits in the encoded codeword, to obtain a permutated encoded codeword; according to the length of the signalling, punching the permutated encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence, which is used for mapping, and then mapping the tuple sequence, which is used for mapping, into a signalling symbol according to a predetermined mapping rule.

Optionally, the step of extending signalling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword comprises: scrambling the signalling, then conducting BCH coding on the scrambled signalling, extending an obtained BCH codeword to obtain an extended BCH codeword as the extended codeword, and conducting LDPC coding on the extended BCH codeword to obtain an LDPC codeword as the encoded codeword.

Optionally, the step of extending an obtained BCH codeword to obtain an extended BCH codeword comprises: the length of the BCH codeword being N_(BCH), the number of bits of an LDPC codeword contained in each bit group being Q, the extended codeword having a length of K_(LDPC) being formed by sequentially splicing K_(LDPC)/Q bit groups, and if the number of completely extended bit groups N_(Pad) is greater than zero, then

${N_{Pad} = {\left\lfloor \frac{K_{LDPC} - N_{BCH}}{Q} \right\rfloor > 0}},$

and then filling the π(0)th group to the π(N_(Pad)−1)th group in the extended BCH codeword with zeros; if the number N _(Pad) of the remaining extended bits is greater than zero, i.e. N _(Pad)=K_(LDPC)−N_(BCH)−QN_(Pad)>0, then filling the first K_(LDPC)−N_(BCH)−QN_(Pad) bits of the π(N_(Pad))th group with zeros; and filling bits which have not been filled with zeros of the extended BCH codeword with the BCH codeword from front to back.

Optionally, the π(0)th group, π(1)th group, . . . ,

$\pi\left( {\frac{K_{LDPC}}{Q} - 1} \right)$

th group in the extended BCH codeword are a predetermined extension pattern table.

Optionally, in the step of conducting predetermined coding on the extended codeword to obtain the encoded codeword, the predetermined coding uses LDPC coding determined by a predetermined LDPC code table.

Optionally, the method comprises conducting first parity bit permutation on the parity bit portion to obtain a first permutated parity bits; dividing the first permutated parity bits into several continuous bit groups, exchanging the positions of the bit groups so that the π_(p)(k)th bit group before the exchange becomes the k th bit group after the exchange to obtain a second permutated parity bits; and sequentially splicing information bits and the second permutated parity bits to obtain the permutated encoded codeword.

Optionally, in the step of exchanging the positions of the bit groups so that the π_(p)(k)th bit group before the exchange becomes the k th bit group after the exchange, it is determined according to a predetermined position permutation table.

Optionally, the predetermined punching rule comprises the steps of: calculating a first punching number by means of a first punching calculation formula according to the length of the signalling; calculating a second punching number by means of a second punching calculation formula according to the first punching number; and removing the second punching number of last bits of the permutated encoded codeword to obtain the punched encoded codeword.

Optionally, the first punching calculation formula uses:

the first punching number N_(punc_temp)=└A* (K_(LDPC)−K_(sig)−L_(p))+B┘,

wherein the values of the first constant A and the second constant B enable signalling with different lengths to have close receiving thresholds after being subjected to coding and modulation, in the formula, K_(LDPC) is the length of the extended BCH codeword, K_(sig) is the signalling length, L_(p) is a definition of the length of parity bits of the BCH codeword, and A and B are two constant parameters, respectively valued as:

${A = \frac{110}{256}},{B = 6408.}$

Optionally, the second punching calculation formula uses:

the second punching number,

$N_{punc} = {N_{{punc\_ tem}p} - \left( {{\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{{punc\_ tem}p}}{\eta_{mod}} \right\rceil\eta_{mod}} - N_{BCH} - N_{LDPC} + K_{LDPC} + N_{{punc\_ tem}p}} \right)}$

wherein N_(punc_temp) is the first punching number calculated by the first punching calculation formula, N_(BCH) is the length of the BCH codeword obtained after conducting BCH coding on scrambled signalling, K_(LDPC) is the length of the extended BCH codeword, N_(LDPC) is the length of the encoded codeword after being subjected to LDPC coding, and η_(mod) is the number of orders of predetermined constellation mapping.

Optionally, the step of conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence comprises removing zeros added to the punched encoded codeword in an extension operation, conducting bit demultiplexing on an obtained encoded codeword with zeros removed to obtain a tuple sequence, and conducting a rotation operation on the tuple sequence to obtain a tuple sequence, which is used for mapping.

Optionally, the step of conducting bit demultiplexing on a encoded codeword with zeros removed to obtain a tuple sequence comprises: successively writing the encoded codeword with zeros removed into a matrix containing η_(mod) columns and

$\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{{punc\_ tem}p}}{\eta_{mod}} \right\rceil$

rows according to columns; and sequentially reading out from the matrix by rows, and forming one tuple with η_(mod) bits in each row to obtain the tuple sequence containing

$\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{{punc\_ tem}p}}{\eta_{mod}} \right\rceil$

tuples.

Optionally, the step of mapping the tuple sequence, which is used for mapping, into a signalling symbol according to the predetermined mapping rule comprises: mapping the tuple sequence, which is used for mapping, into the signalling symbol according to a mapping rule table containing predetermined mapping parameters.

In addition, an embodiment of the present invention further provides a signalling demodulation and decoding method, characterized in that the method comprises the steps of: demapping a receiving end signalling symbol corresponding to a sending end signalling symbol according to a predetermined mapping rule to obtain a log likelihood ratio; conducting corresponding inverse second predetermined processing, inverse punching and inverse permutation on the log likelihood ratio according to the steps of parity bit permutation, punching and second predetermined processing in the signalling coding and modulation method at a sending end to obtain a log likelihood ratio of a receiving end encoded codeword corresponding to a sending end encoded codeword; and conducting corresponding decoding, inverse extension and inverse first predetermined processing on the log likelihood ratio of the receiving end encoded codeword according to the steps of first predetermined processing, extension and predetermined coding in the signalling coding and modulation method at a sending end to obtain signalling.

In addition, an embodiment of the present invention further provides a signalling coding and modulation device, characterized in that the device comprises: an extension coding module: extending signalling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword; a permutation module: conducting parity bit permutation on parity bits in the encoded codeword and then splicing the permutated parity bits to the information bits in the encoded codeword, to obtain a permutated encoded codeword; a punching module: according to the length of the signalling, punching the permutated encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and a processing and mapping module: conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence, which is used for mapping, and then mapping the obtained tuple sequence into a signalling symbol according to a predetermined mapping rule.

In addition, an embodiment of the present invention further provides a signalling demodulation and decoding device, characterized in that the device comprises: a demapping module: demapping a receiving end signalling symbol corresponding to a sending end signalling symbol according to a predetermined mapping rule to obtain a log likelihood ratio; a corresponding permutation deprocessing module: conducting corresponding inverse second predetermined processing, inverse punching and inverse permutation on the log likelihood ratio according to the steps of parity bit permutation, punching and second predetermined processing in the signalling coding and modulation device at a sending end to obtain a log likelihood ratio of a receiving end encoded codeword corresponding to a sending end encoded codeword; and a decoding module: conducting corresponding decoding, inverse extension and inverse first predetermined processing on the log likelihood ratio of the receiving end encoded codeword according to the steps of first predetermined processing, extension and predetermined coding in the signalling coding and modulation device at a sending end to obtain signalling. Compared with the prior art, the technical solution of the present invention provides the following advantages:

taking providing signalling for a high throughput data service with a relatively high receiving threshold as an objective, the present invention conducts a series of extension, coding, parity bit permutation, punching and mapping processing on signalling to obtain a signalling symbol, which provides a high-efficient and robust signalling coding and modulation method not only for signalling of a high throughput data service, but also particularly for signalling with a variable length.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

FIG. 1 is a schematic diagram of the overall procedure of a signalling coding and modulation method in an embodiment of the present invention;

FIG. 2 is a schematic diagram of the specific procedure of a signalling coding and modulation method in an embodiment of the present invention; and

FIG. 3 is a schematic diagram of the procedure of a signalling demodulation and decoding method in an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The inventor has found that in the prior art, there is no signalling coding and modulation method designed for a service with a relatively high receiving threshold (e.g. greater than 25 dB) in a predetermined channel.

With regard to the above problem, the inventor provides, through research, a signalling coding and modulation method and a demapping and decoding method to conduct a series of extension, coding, parity bit permutation, punching and mapping processing on signalling, and further designs and provides specific technical parameters of extension, coding, parity bit permutation, punching, mapping, etc. to conduct a high-efficient and robust signalling coding and modulation method.

To make the foregoing objectives, features, and advantages of the present invention more evident and comprehensible, the following describes specific implementation manners of the present invention in details with reference to the accompanying drawings.

For example, in a DVB-T2 system, one primary mode is an LDPC code with a code rate of 2/3 in cooperation with 256QAM mapping, a receiving threshold of the mode has reached 17 dB to 18 dB, and with the continuous increase of system capacity, for example, a coding and modulation mode of an LDPC code with a code rate of 2/3 in cooperation with 1024QAM mapping or even in cooperation with 4096QAM mapping would also emerge, and at this time, the receiving threshold would reach 25 dB or even 30 dB. It can be seen that the receiving threshold of a data service is determined based on a coding and modulation mode of a system. The present invention does not limit the specific numerical value of the receiving threshold, which is above a predetermined high threshold value, of a data service. In the embodiments below, a data service with a receiving threshold being greater than 25 dB in a white noise channel is chosen for description.

FIG. 1 is a schematic diagram of the overall procedure of a signalling coding and modulation method in an embodiment of the present invention;

In the embodiment of the present invention, a signalling coding and modulation method at a transmitting end comprises the steps of:

step S1-1: extending signalling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword;

step S1-2: conducting parity bit permutation on the encoded codeword to obtain a permutated encoded codeword;

step S1-3: according to the length of the signalling, punching the permutated encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and

step S1-4: conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence, which is used for mapping, and then mapping the obtained tuple sequence into a signalling symbol according to a predetermined mapping rule.

It can be seen from step S1-1 to step S1-4 above that the signalling coding and modulation method conducts a series of extension, coding, parity bit permutation, punching and mapping processing on signalling, and furthermore, as a preferred example, the following processing is complementarily conducted on the basis of step S1-1 to step S1-4. That is, firstly scrambling is conducted on the signalling, and then BCH coding, extension, LDPC coding, parity bit permutation, punching, zero removing, bit demultiplexing, bit rotation and constellation mapping are successively conducted to obtain a signalling symbol. Specifically, FIG. 2 is a schematic diagram of the specific procedure of a signalling coding and modulation method in an embodiment of the present invention, as shown in FIG. 2:

A signalling coding and modulation method comprises the steps of:

step S1-1*: scrambling signalling with a length being K_(sig) bits to obtain scrambled signalling with a length being K_(sig) bits;

step S1-2*: conducting BCH coding on the scrambled signalling, i.e. conducting calculation according to information bits to obtain 168 BCH parity bits; and splicing the BCH parity bits to the end of the scrambled signalling to obtain a BCH codeword with a length being N_(BCH)=K_(sig)+168 bits, wherein the BCH coding is specifically used to describe the problem of confirming the number of parity bits, that is, the number of the parity bits (168) is determined according to coding characteristics (e.g. BCH characteristics) in combination with the consideration of an overall block error ratio of signalling coding and modulation, for example, 168 BCH parity bits are able to correct 12-bit errors in signalling with a length being smaller than 6480 bits, while the number of 12-bit bits is further determined based on an overall block error ratio for improving signalling coding and modulation, and therefore the signalling may further be protected on the basis of an LDPC code by means of the processing in step S1-2*, thereby effectively improving the overall performance of signalling coding and modulation;

step S1-3*: extending the BCH codeword to obtain an extended BCH codeword with a length being K_(LDPC)=6480 bits;

step S1-4*: conducting LDPC coding on the obtained extended BCH codeword, to obtain an LDPC codeword with a length being N_(LDPC)=16200 bits;

step S1-5*: the LDPC codeword containing information bits of the first K_(LDPC) bits and parity bits of the last N_(LDPC)−K_(LDPC) bits, conducting parity bit permutation on the parity bits to obtain permutated parity bits, and splicing the permutated parity bits to the end of the information bits to obtain a permutated LDPC codeword;

step S1-6*: calculating the number of punchings according to the length of the signalling (K_(sig) bits), and punching a corresponding number of parity bits in the permutated LDPC codeword according to a predetermined punching rule, to obtain a punched LDPC codeword;

step S1-7*: removing zeros added in an extension operation from the punched LDPC codeword to obtain an LDPC codeword with zeros removed;

step S1-8*: conducting bit demultiplexing on the LDPC codeword with zeros removed to obtain a tuple sequence, wherein each tuple contains η_(mod)=8 bits;

step S1-9*: conducting bit rotation on each tuple in the tuple sequence to obtain a tuple sequence, which is used for mapping; and

step S1-10*: mapping the tuple sequence, which is used for mapping, into a signalling symbol according to a predetermined mapping rule.

The extension processing in step S1-3* above is specifically described as follows. In this embodiment, step S1-3* comprises the specific steps of:

defining the extended BCH codeword to be formed by sequentially splicing K_(LDPC)/Q bit groups, wherein each bit group contains Q bits, the number of bits Q within the bit group is the side length of an LDPC codeword sub-block, the value of Q is 360, and the K_(LDPC)/Q bit groups respectively form the 0th group, the 1st group, until the K_(LDPC)/Q−1th bit group from front to back;

if the number N_(Pad) of completely extended bit groups is greater than zero, wherein

${N_{Pad} = \left\lfloor \frac{K_{LDPC} - N_{BCH}}{Q} \right\rfloor},$

filling the π(0)th group to the π(N_(Pad)−1)th group in the extended BCH codeword with zeros, wherein

${\pi(0)},{\pi(1)},\ldots\mspace{14mu},{\pi\left( {\frac{K_{LDPC}}{Q} - 1} \right)}$

is defined by the extension pattern table in Table 1;

if the number N _(Pad) of the remaining extended bits is greater than zero, wherein N _(Pad)=K_(LDPC)−N_(BCH)−QN_(Pad), then filling the first N _(Pad) bits of the π(N_(Pad))th group with zeros; and filling bits which have not been filled with zeros of the extended BCH codeword with the BCH codeword with a length being N_(BCH) from front to back.

The extension patterns in Table 1 below are jointly designed according to the capacity of each bit in constellation mapping and degree distribution of different variable nodes in the information bits of the LDPC codeword, and by optimizing the extension patterns, the coding and modulation performance may be effectively improved.

TABLE 1 Extension pattern table ${\pi(0)},{\pi(1)},\ldots\mspace{14mu},{\pi\left( {\frac{K_{LDPC}}{Q} - 1} \right)}$ 15 7  8 11 5 10 16 4 12 3 0 6 9 1 14 17 2 13

The LDPC coding processing in step S1-4* above is specifically described as follows, N_(LDPC)−K_(LDPC) parity bits p=[p₀, p₁, . . . , p_(N) _(LDPC) _(-K) _(LDPC) ₋₁] are generated according to the extended BCH codeword m=[m₀, m₁, . . . , m_(K) _(LDPC-1) ], and the parity bits are sequentially spliced to the end of the extended BCH codeword to obtain the LDPC codeword. Step S1-4* comprises the specific steps of:

initializing p_(i)=0 (i=0, 1, . . . , N_(LDPC)−K_(LDPC)−1);

accumulating the parity bits of which the first row of digits is an address in the LDPC code table in Table 2 below, defining a set formed by the first row of digits as Φ₀, firstly conducting p_(k)=p_(k)⊕m₀ on all k satisfying k∈Φ₀, and then with regard to all k satisfying k∈Φ₀, conducting

${p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{1}}},$

then with regard to all k satisfying k∈Φ₀, conducting

${p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{2}}},$

and by analogy, finally, with regard to all k satisfying k∈Φ₀, conducting

${p_{{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{Q - 1}}};$

accumulating the parity bits of which the second row of digits is an address in Table 2 below, defining a set formed by the second row of digits as Φ₁, firstly conducting p_(k)=p_(k)αm_(Q) on all k satisfying k∈Φ₁, and then with regard to all k satisfying k∈Φ₁, conducting

${p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{Q + 1}}},$

then with regard to all k satisfying k∈Φ₁, conducting

${p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{Q + 2}}},$

and by analogy, finally, with regard to all k satisfying k∈Φ₁, conducting

${p_{{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{{2Q} - 1}}};$

and

by analogy, accumulating the parity bits of all the rows in the table until the

$\frac{K_{LDPC} - N_{BCH}}{Q}$

th

$\frac{K_{LDPC}}{Q}$

row, firstly conducting p_(k)=p_(k)⊕m_(K) _(LDPC) _(-Q) on all k satisfying

${k \in \Phi_{\frac{K_{LDPC}}{Q} - 1}},$

and then with regard to all k satisfying

${k \in \Phi_{\frac{K_{LDPC}}{Q} - 1}},$

conducting

${p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + \frac{N_{LDPC} - K_{LDPC}}{Q}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{K_{LDPC} - Q + 1}}},$

then with regard to all k satisfying

${k \in \Phi_{\frac{K_{LDPC}}{Q} - 1}},$

conducting

$p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} = {p_{{({k + {2\frac{N_{LDPC} - K_{LDPC}}{Q}}})}mo{d{({N_{LDPC} - K_{LDPC}})}}} \oplus m_{K_{LDPC} - Q + 2}}$

and by analogy, finally, with regard to all k satisfying

${k \in \Phi_{\frac{K_{LDPC}}{Q} - 1}},$

conducting

${p_{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}{{mod}{({N_{LDPC} - K_{LDPC}})}}}}} = {p_{({k + {{({Q - 1})}\frac{N_{LDPC} - K_{LDPC}}{Q}{{mod}{({N_{LDPC} - K_{LDPC}})}}}}} \oplus m_{K_{LDPC} - 1}}};$

and

conducting p₁=p₁⊕p₀, then conducting p₂=p₂⊕+p₁, and then conducting p₃=p₃⊕p₂, and by analogy finally conducting

p _(N) _(LDPC) _(-K) _(LDPC) ₋₁ =p _(N) _(LDPC) _(-K) _(LDPC) ₋₁ ⊕p _(N) _(LDPC) _(-K) _(LDPC) ₋₂; and

finally, after all the parity bits are sequentially spliced to the end of the extended BCH codeword, obtaining the LDPC codeword.

TABLE 2 LDPC code table Row 1: 27 430 519 828 1897 1943 2513 2600 2640 3310 3415 4266 5044 5100 5328 5483 5928 6204 6392 6416 6602 7019 7415 7623 8112 8485 8724 8994 9445 9667 Row 2: 27 174 188 631 1172 1427 1779 2217 2270 2601 2813 3196 3582 3895 3908 3948 4463 4955 5120 5809 5988 6478 6604 7096 7673 7735 7795 8925 9613 9670 2909 Row 3: 27 370 617 852 910 1030 1326 1521 1606 2118 2248 3214 3413 3623 3742 3752 4317 4694 5300 5687 6039 6100 6232 6491 6621 6860 7304 8542 8634 Row 4: 990 1753 7635 8540 Row 5: 933 1415 5666 8745 Row 6: 27 6567 8707 9216 Row 7: 2341 8692 9580 9615 Row 8: 260 1092 5839 6080 Row 9: 352 3750 4847 7726 Row 10: 4610 6580 9506 9597 Row 11: 2512 2974 4814 9348 Row 12: 1461 4021 5060 7009 Row 13: 1796 2883 5553 8306 Row 14: 1249 5422 7057 Row 15: 3965 6968 9422 Row 16: 1498 2931 5092 Row 17: 27 1090 6215 Row 18: 26 4232 6354

The parity bit permutation processing in step S1-5* above is specifically described as follows. In this embodiment, step S1-5* comprises the specific steps of:

conducting first parity bit permutation on the parity bits p=[p₀, p₁, . . . , p_(N) _(LDPC) _(-K) _(LDPC) ₋₁] to obtain a first permutated parity bits u=[u₀, u₁, . . . , u_(N) _(LDPC) _(-K) _(LDPC) ₋₁],

wherein

${u_{{Qt} + s} = {p_{{\frac{N_{LDPC} - K_{LDPC}}{Q}s} + t}\left( {{0 \leq s < Q},{0 \leq t < \frac{N_{LDPC} - K_{LDPC}}{Q}}} \right)}};$

dividing the first permutated parity bits into

$\frac{N_{LDPC} - K_{LDPC}}{Q}$

continuous bit groups, wherein each bit group contains Q bits, exchanging the positions of the bit groups so that the π_(p)(k)th bit group

$\left( {0 \leq k < \frac{N_{LDPC} - K_{LDPC}}{Q}} \right)$

before the exchange becomes the k th bit group after the exchange to obtain a second permutated parity bits,

wherein a permutation sequence

${\pi_{p}(0)},{\pi_{p}(1)},\ldots\mspace{14mu},{\pi_{p}\left( \frac{N_{LDPC} - K_{LDPC}}{Q} \right)}$

is defined in the predetermined position permutation table in Table 3; and

sequentially splicing information bits and the second permutated parity bits to obtain the permutated LDPC codeword.

The permutation sequence in Table 3 below is jointly designed according to the capacity of each bit in constellation mapping and degree distribution of different variable nodes in the parity bits of the LDPC codeword, and by optimizing the permutation sequence, the coding and modulation performance may be effectively improved.

TABLE 3 Predetermined position permutation table $\begin{matrix} {{\pi_{p}(0)},{\pi_{p}(1)},\ldots\mspace{14mu},{\pi_{p}\left( \frac{N_{LDPC} - K_{LDPC}}{Q} \right)}} & \; \end{matrix}$ 26 5 11 15 6 10 3 9 24 0 4 13 14 19 25 12 7 17 2 16 21 18 1 23 22 8 20

The specific numerical value of the number of bits in Table 3 is described as follows: in practical applications, in a transmission standard, information bits of the first several number of bits (e.g. 18 bits) are taken into consideration, and the parity bits are following the information bits so that the counting of the number of bits of the parity bits starts from the number of bits of that information bit (counting from the 18th bit). It needs to be noted that in Table 3 of this embodiment, what is described is to start counting from the 0th bit with regard to the parity bits, and if the preceding information bits and the following parity bits are comprehensively taken into consideration, the counting for the parity bits should accumulate the number of bits of the information bits. Those skilled in the art would readily understand that this is not limited by the difference of the starting point of specific numerical values of counting, so as to infer other specific parameters in a similar manner herein.

The punching processing in step S1-6* above is specifically described as follows. In this embodiment, step S1-6* comprises the specific steps of:

calculating the first punching number N_(punc_temp) by means of a first punching formula according to the length K_(sig) of the signalling, the first punching formula being N_(punc_temp)=└A(K_(LDPC)−K_(sig)−168)+B┘, and in this embodiment, the length of the extended BCH codeword being K_(LDPC)=6480 and A and B being constants

${{A = \frac{49}{256}},{B = {8246}}},$

wherein 168 in K_(LDPC)−K_(sig)−168 is the number of bits L_(p) of parity bits of the BCH, wherein the constant A and the constant B are designed and determined in order to enable the signalling coding and modulation scheme to have a close receiving threshold with different K_(sig);

calculating the second punching number N_(punc) by means of a second punching formula according to the first punching number N_(punc_temp) the second punching formula being:

${N_{punc} = {N_{punc\_ temp} - \left( {{\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil\eta_{mod}} - N_{BCH} - N_{LDPC} + K_{LDPC} + N_{punc\_ temp}} \right)}};$

and

removing the last N_(punc) bits of the LDPC codeword to obtain a punched LDPC codeword.

The bit demultiplexing processing in step S1-8* above is specifically described as follows. In this embodiment, step S1-8* comprises the specific steps of:

successively writing the LDPC codeword with zeros removed into a matrix containing η_(mod) columns and

$\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil$

rows according to columns; and

sequentially reading out from the matrix by rows, and forming one tuple with η_(mod) bits in each row so as to obtain the tuple sequence containing

$\left\lceil \frac{N_{BCH} + N_{LDPC} - K_{LDPC} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil$

tuples.

The bit rotation processing in step S1-9* above is specifically described as follows. In this embodiment, step S1-9* comprises the specific steps of:

keeping the first tuple in the tuple sequence unchanged; rotating the second tuple in the tuple sequence by one bit, i.e. the first bit of the tuple after rotation is the η_(mod) th bit in the original tuple, the second bit of the tuple after rotation is the first bit in the original tuple, the third bit of the tuple after rotation is the second bit of the original tuple, and by analogy, the η_(mod) th bit of the tuple after rotation is the η_(mod)−1th bit of the original tuple; by the same reasoning, rotating the third tuple of the tuple sequence by two bits; by the same reasoning, rotating the fourth tuple of the tuple sequence by three bits; and by analogy, rotating all the tuples in the tuple sequence to obtain a rotated tuple sequence.

In other words, the first tuple (the tuple number y corresponds to 0) of the tuple sequence is kept unchanged, and the yth tuple (the tuple number y corresponds to 1, 2, 3 . . . ) of the tuple sequence is rotated by y−1 bits, thereby correspondingly rotating all the tuples in the tuple sequence to obtain the rotated tuple sequence.

It is noted that rotating the η_(MOD)+1th, the 2η_(MOD)+1th tuples, etc. by an integral multiple of η_(MOD) bits is equivalent to no rotation, and rotating the η_(MOD)+2th, the 2η_(MOD)+2 th, tuples, etc. is equivalent to rotating one bit.

The predetermined mapping rule in step S1-10* above is specifically described as follows. In this embodiment, step S1-10* comprises the specific steps of:

mapping each tuple of the tuple sequence into one signalling symbol, wherein the mapping rule is as shown in the constellation mapping rule table in Table 4, for example, when one tuple is “00000001”, it will be mapped into 1.2668+0.8034i.

TABLE 4 Constellation mapping rule table Tuple Signalling symbol 00000000  1.2412 + 1.0688i 00000001  1.2668 + 0.8034i 00000010  0.9860 + 1.1758i 00000011  1.0365 + 0.9065i 00000100  1.2111 + 0.5135i 00000101  1.4187 + 0.6066i 00000110  1.0103 + 0.4879i 00000111  1.0380 + 0.6906i 00001000  0.6963 + 1.3442i 00001001  0.7089 + 1.1122i 00001010  0.1256 + 1.4745i 00001011  0.8331 + 0.9455i 00001100  0.6615 + 0.6012i 00001101  0.6894 + 0.7594i 00001110  0.8373 + 0.5633i 00001111  0.8552 + 0.7410i 00010000  1.2666 + 0.1027i 00010001  1.4915 + 0.1198i 00010010  1.0766 + 0.0945i 00010011  0.9007 + 0.0848i 00010100  1.2454 + 0.3064i 00010101  1.4646 + 0.3600i 00010110  1.0570 + 0.2995i 00010111  0.9140 + 0.2530i 00011000  0.5461 + 0.0679i 00011001  0.5681 + 0.1947i 00011010  0.6874 + 0.0537i 00011011  0.7375 + 0.1492i 00011100  0.6290 + 0.4553i 00011101  0.6007 + 0.3177i 00011110  0.7885 + 0.4231i 00011111  0.7627 + 0.2849i 00100000  0.0816 + 1.1632i 00100001  0.0830 + 0.9813i 00100010  0.2528 + 1.2315i 00100011  0.2502 + 1.0100i 00100100  0.0732 + 0.6827i 00100101  0.0811 + 0.8293i 00100110  0.2159 + 0.6673i 00100111  0.2359 + 0.8283i 00101000  0.4302 + 1.4458i 00101001  0.5852 + 0.9680i 00101010  0.4528 + 1.2074i 00101011  0.4167 + 1.0099i 00101100  0.5035 + 0.6307i 00101101  0.5359 + 0.7954i 00101110  0.3580 + 0.6532i 00101111  0.3841 + 0.8207i 00110000  0.0576 + 0.0745i 00110001  0.0581 + 0.2241i 00110010  0.1720 + 0.0742i 00110011  0.1753 + 0.2222i 00110100  0.0652 + 0.5269i 00110101  0.0611 + 0.3767i 00110110  0.1972 + 0.5178i 00110111  0.1836 + 0.3695i 00111000  0.4145 + 0.0709i 00111001  0.4266 + 0.2100i 00111010  0.2912 + 0.0730i 00111011  0.2982 + 0.2177i 00111100  0.4766 + 0.4821i 00111101  0.4497 + 0.3448i 00111110  0.3334 + 0.5025i 00111111  0.3125 + 0.3601i 01000000 −1.2412 + 1.0688i 01000001 −1.2668 + 0.8034i 01000010 −0.9860 + 1.1758i 01000011 −1.0365 + 0.9065i 01000100 −1.2111 + 0.5135i 01000101 −1.4187 + 0.6066i 01000110 −1.0103 + 0.4879i 01000111 −1.0380 + 0.6906i 01001000 −0.6963 + 1.3442i 01001001 −0.7089 + 1.1122i 01001010 −0.1256 + 1.4745i 01001011 −0.8331 + 0.9455i 01001100 −0.6615 + 0.6012i 01001101 −0.6894 + 0.7594i 01001110 −0.8373 + 0.5633i 01001111 −0.8552 + 0.7410i 01010000 −1.2666 + 0.1027i 01010001 −1.4915 + 0.1198i 01010010 −1.0766 + 0.0945i 01010011 −0.9007 + 0.0848i 01010100 −1.2454 + 0.3064i 01010101 −1.4646 + 0.3600i 01010110 −1.0570 + 0.2995i 01010111 −0.9140 + 0.2530i 01011000 −0.5461 + 0.0679i 01011001 −0.5681 + 0.1947i 01011010 −0.6874 + 0.0537i 01011011 −0.7375 + 0.1492i 01011100 −0.6290 + 0.4553i 01011101 −0.6007 + 0.3177i 01011110 −0.7885 + 0.4231i 01011111 −0.7627 + 0.2849i 01100000 −0.0816 + 1.1632i 01100001 −0.0830 + 0.9813i 01100010 −0.2528 + 1.2315i 01100011 −0.2502 + 1.0100i 01100100 −0.0732 + 0.6827i 01100101 −0.0811 + 0.8293i 01100110 −0.2159 + 0.6673i 01100111 −0.2359 + 0.8283i 01101000 −0.4302 + 1.4458i 01101001 −0.5852 + 0.9680i 01101010 −0.4528 + 1.2074i 01101011 −0.4167 + 1.0099i 01101100 −0.5035 + 0.6307i 01101101 −0.5359 + 0.7954i 01101110 −0.3580 + 0.6532i 01101111 −0.3841 + 0.8207i 01110000 −0.0576 + 0.0745i 01110001 −0.0581 + 0.2241i 01110010 −0.1720 + 0.0742i 01110011 −0.1753 + 0.2222i 01110100 −0.0652 + 0.5269i 01110101 −0.0611 + 0.3767i 01110110 −0.1972 + 0.5178i 01110111 −0.1836 + 0.3695i 01111000 −0.4145 + 0.0709i 01111001 −0.4266 + 0.2100i 01111010 −0.2912 + 0.0730i 01111011 −0.2982 + 0.2177i 01111100 −0.4766 + 0.4821i 01111101 −0.4497 + 0.3448i 01111110 −0.3334 + 0.5025i 01111111 −0.3125 + 0.3601i 10000000  1.2412 − 1.0688i 10000001  1.2668 − 0.8034i 10000010  0.9860 − 1.1758i 10000011  1.0365 − 0.9065i 10000100  1.2111 − 0.5135i 10000101  1.4187 − 0.6066i 10000110  1.0103 − 0.4879i 10000111  1.0380 − 0.6906i 10001000  0.6963 − 1.3442i 10001001  0.7089 − 1.1122i 10001010  0.1256 − 1.4745i 10001011  0.8331 − 0.9455i 10001100  0.6615 − 0.6012i 10001101  0.6894 − 0.7594i 10001110  0.8373 − 0.5633i 10001111  0.8552 − 0.7410i 10010000  1.2666 − 0.1027i 10010001  1.4915 − 0.1198i 10010010  1.0766 − 0.0945i 10010011  0.9007 − 0.0848i 10010100  1.2454 − 0.3064i 10010101  1.4646 − 0.3600i 10010110  1.0570 − 0.2995i 10010111  0.9140 − 0.2530i 10011000  0.5461 − 0.0679i 10011001  0.5681 − 0.1947i 10011010  0.6874 − 0.0537i 10011011  0.7375 − 0.1492i 10011100  0.6290 − 0.4553i 10011101  0.6007 − 0.3177i 10011110  0.7885 − 0.4231i 10011111  0.7627 − 0.2849i 10100000  0.0816 − 1.1632i 10100001  0.0830 − 0.9813i 10100010  0.2528 − 1.2315i 10100011  0.2502 − 1.0100i 10100100  0.0732 − 0.6827i 10100101  0.0811 − 0.8293i 10100110  0.2159 − 0.6673i 10100111  0.2359 − 0.8283i 10101000  0.4302 − 1.4458i 10101001  0.5852 − 0.9680i 10101010  0.4528 − 1.2074i 10101011  0.4167 − 1.0099i 10101100  0.5035 − 0.6307i 10101101  0.5359 − 0.7954i 10101110  0.3580 − 0.6532i 10101111  0.3841 − 0.8207i 10110000  0.0576 − 0.0745i 10110001  0.0581 − 0.2241i 10110010  0.1720 − 0.0742i 10110011  0.1753 − 0.2222i 10110100  0.0652 − 0.5269i 10110101  0.0611 − 0.3767i 10110110  0.1972 − 0.5178i 10110111  0.1836 − 0.3695i 10111000  0.4145 − 0.0709i 10111001  0.4266 − 0.2100i 10111010  0.2912 − 0.0730i 10111011  0.2982 − 0.2177i 10111100  0.4766 − 0.4821i 10111101  0.4497 − 0.3448i 10111110  0.3334 − 0.5025i 10111111  0.3125 − 0.3601i 11000000 −1.2412 − 1.0688i 11000001 −1.2668 − 0.8034i 11000010 −0.9860 − 1.1758i 11000011 −1.0365 − 0.9065i 11000100 −1.2111 − 0.5135i 11000101 −1.4187 − 0.6066i 11000110 −1.0103 − 0.4879i 11000111 −1.0380 − 0.6906i 11001000 −0.6963 − 1.3442i 11001001 −0.7089 − 1.1122i 11001010 −0.1256 − 1.4745i 11001011 −0.8331 − 0.9455i 11001100 −0.6615 − 0.6012i 11001101 −0.6894 − 0.7594i 11001110 −0.8373 − 0.5633i 11001111 −0.8552 − 0.7410i 11010000 −1.2666 − 0.1027i 11010001 −1.4915 − 0.1198i 11010010 −1.0766 − 0.0945i 11010011 −0.9007 − 0.0848i 11010100 −1.2454 − 0.3064i 11010101 −1.4646 − 0.3600i 11010110 −1.0570 − 0.2995i 11010111 −0.9140 − 0.2530i 11011000 −0.5461 − 0.0679i 11011001 −0.5681 − 0.1947i 11011010 −0.6874 − 0.0537i 11011011 −0.7375 − 0.1492i 11011100 −0.6290 − 0.4553i 11011101 −0.6007 − 0.3177i 11011110 −0.7885 − 0.4231i 11011111 −0.7627 − 0.2849i 11100000 −0.0816 − 1.1632i 11100001 −0.0830 − 0.9813i 11100010 −0.2528 − 1.2315i 11100011 −0.2502 − 1.0100i 11100100 −0.0732 − 0.6827i 11100101 −0.0811 − 0.8293i 11100110 −0.2159 − 0.6673i 11100111 −0.2359 − 0.8283i 11101000 −0.4302 − 1.4458i 11101001 −0.5852 − 0.9680i 11101010 −0.4528 − 1.2074i 11101011 −0.4167 − 1.0099i 11101100 −0.5035 − 0.6307i 11101101 −0.5359 − 0.7954i 11101110 −0.3580 − 0.6532i 11101111 −0.3841 − 0.8207i 11110000 −0.0576 − 0.0745i 11110001 −0.0581 − 0.2241i 11110010 −0.1720 − 0.0742i 11110011 −0.1753 − 0.2222i 11110100 −0.0652 − 0.5269i 11110101 −0.0611 − 0.3767i 11110110 −0.1972 − 0.5178i 11110111 −0.1836 − 0.3695i 11111000 −0.4145 − 0.0709i 11111001 −0.4266 − 0.2100i 11111010 −0.2912 − 0.0730i 11111011 −0.2982 − 0.2177i 11111100 −0.4766 − 0.4821i 11111101 −0.4497 − 0.3448i 11111110 −0.3334 − 0.5025i 11111111 −0.3125 − 0.3601i

In summary, the constellation mapping rule table in Table 4 provides a 256QAM mapping rule. If a constellation mapping rule table different from Table 4 is used, then parameter values in a corresponding extension pattern table and a predetermined position permutation table and the specific values of the constants A and B in the first punching formula in the punching processing in step S1-6* will also change accordingly.

The 256QAM constellation mapping rule table, parameter values in the corresponding extension pattern table and the predetermined position permutation table and the specific values of the constants A and B in the first punching formula in the punching processing in step S1-6* used in this embodiment are optimally designed, which can effectively reduce the computation complexity of coding and modulation, and demodulation and decoding of a system, and improve system performance.

In the present invention, not only all of step S1-1* to step S1-10* as above are necessarily contained in the signalling coding and modulation method, but also one or at least any two free combinations of step S1-1* to step S1-10* above may be selectively utilized to conduct coding and modulation on signalling and correspondingly conduct demodulation and decoding, and the specific steps of one or at least any two free combinations involved may be obtained correspondingly and will not be listed one by one for description, and only [1] a signalling coding and modulation method containing the above extension processing, [2] a signalling coding and modulation method containing the above parity bit permutation processing, and [3] a signalling coding and modulation method containing the above punching processing, are merely taken as examples for description.

With regard to [1] a signalling coding and modulation method containing the above extension processing: an embodiment of the present invention further provides a signalling coding and modulation method, comprising the steps of:

conducting BCH coding on the signalling, and extending an obtained BCH codeword to obtain an extended BCH codeword; and processing the extended BCH codeword to obtain a signalling symbol,

wherein if the number N_(Pad) of completely extended groups is greater than zero, then the π(0)th group until the π(N_(Pad)−1)th group in the extended BCH codeword are filled with zeros; if the number N_(Pad) of the remaining extended bits is greater than zero, then the first K_(LDPC)−N_(BCH)−QN_(Pad) bits of the π(N_(Pad))th group are filled with zeros; and bit positions which have not been filled with zeros in the extended BCH codeword are filled with the BCH codeword from front to back.

By the same reasoning, the π(0)th group, π(1)th group, . . . ,

$\pi\left( {\frac{K_{LDPC}}{Q} - 1} \right)$

th group are defined by the extension pattern table in Table 1 above.

With regard to [2] a signalling coding and modulation method containing the above parity bit permutation processing: an embodiment of the present invention further provides a signalling coding and modulation method, comprising the steps of:

conducting signalling processing to obtain a encoded codeword; conducting parity bit permutation on the encoded codeword to obtain a permutated encoded codeword; processing the permutated encoded codeword to obtain a signalling symbol,

wherein the encoded codeword contains information bits and parity bits; conducting parity bit permutation on the parity bits to obtain permutated parity bits, and splicing the permutated parity bits to the end of the information bits to obtain a permutated LDPC codeword;

conducting first parity bit permutation on the parity bits to obtain a first permutated parity bits; dividing the first permutated parity bits into several continuous bit groups, determining the positions of exchange bit groups by means of the predetermined position permutation table Table 3 so that the π_(p)(k)th bit group before the exchange becomes the k th bit group after the exchange to obtain a second permutated parity bits; and sequentially splicing information bits and the second permutated parity bits to obtain the permutated encoded codeword.

By the same reasoning, the predetermined position permutation table uses the predetermined position permutation table in Table 3 above.

With regard to [3] a signalling coding and modulation method containing the above punching processing: an embodiment of the present invention further provides a signalling coding and modulation method, comprising the steps of:

conducting processing on signalling to obtain a processed encoded codeword; according to the length of the signalling, punching the processed encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and processing the punched encoded codeword to obtain a signalling symbol,

wherein the predetermined punching rule comprises the steps of: calculating a first punching number by means of a first punching calculation formula according to the length of the signalling; calculating a second punching number by means of a second punching calculation formula according to the first punching number; and removing the second punching number of last bits of the processed encoded codeword.

In addition, an embodiment of the present invention further provides a signalling demodulation and decoding method. FIG. 3 shows a schematic diagram of the procedure of a specific embodiment of signalling demodulation and decoding of the present invention. With reference to FIG. 3, signalling demodulation and decoding comprises the steps of:

step S2-1: demapping a receiving end signalling symbol corresponding to a sending end signalling symbol according to a predetermined mapping rule to obtain a log likelihood ratio;

step S2-2: conducting corresponding inverse second predetermined processing, inverse punching and inverse permutation on the log likelihood ratio according to the steps of parity bit permutation, punching and second predetermined processing in the signalling coding and modulation method at a sending end to obtain a log likelihood ratio of a receiving end encoded codeword corresponding to a sending end encoded codeword; and

step S2-3: conducting corresponding decoding, inverse extension and inverse first predetermined processing on the log likelihood ratio of the receiving end encoded codeword according to the steps of first predetermined processing, extension and predetermined coding in the signalling coding and modulation method at a sending end to obtain signalling.

Step S2-1 to step S2-3 at the receiving end are described corresponding to step S1-1 to step S1-4 in the overall procedure at the sending end. When the signalling coding and modulation method does not only conduct a series of extension, coding, parity bit permutation, punching and mapping processing on signalling, but also further conducts at least any complementary processing such as step S1-1* to step S1-10*, e.g. scrambling the signalling, and then successively conducting BCH coding, extension, LDPC coding, parity bit permutation, zero removing, bit demultiplexing, bit rotation and constellation mapping and the like, then correspondingly, signalling demodulation and decoding at the receiving end has the specific steps as follows.

Step S2-2 comprises: according to parity bit permutation, punching, zero removing, bit demultiplexing and bit rotation rules at the transmitting end, conducting corresponding inverse processing on the log likelihood ratio, to obtain a receiving end LDPC encoded codeword log likelihood ratio corresponding to the LDPC encoded codeword; and

step S2-3: according to the scrambling, BCH coding, extension and LDPC coding rules at the transmitting end, conducting decoding and corresponding inverse processing on the LDPC encoded codeword log likelihood ratio at the receiving end to obtain the signalling.

It needs to be noted that in step S2-2, the corresponding inverse processing corresponds to parity bit permutation, punching, zero removing, bit demultiplexing and bit rotation rules at the transmitting end, and the specific implementation does not necessarily need to be conducted in an order opposite to the transmitting end, and the order of specific steps can be altered by various conversions or mutual combinations. In step 2-3, the rule for decoding the LDPC encoded codeword log likelihood ratio at the receiving end corresponds to the LDPC coding rule at the transmitting end. The corresponding inverse processing corresponds to scrambling, BCH coding and extension rules at the transmitting end, and the specific implementation does not necessarily need to be conducted in an order opposite to the transmitting end, and the order of specific steps can be altered by various conversions or mutual combinations. The BCH decoding rule corresponds to the BCH coding rule at the transmitting end.

In particular, the inverse extension step, inverse parity bit permutation step, inverse punching rule and the involved parameters, tables, formulas, etc. used in the signalling demodulation and decoding method respectively correspond to the signalling coding and modulation method in the embodiment above, which will not be described again.

In addition, an embodiment of the present invention further provides a signalling coding and modulation device, characterized in that the device comprises: an extension coding module: extending signalling which has been subjected to first predetermined processing according to an extension pattern table to obtain an extended codeword, and conducting predetermined coding on the extended codeword to obtain a encoded codeword; a permutation module: conducting parity bit permutation on parity bits in the encoded codeword and then splicing the permutated parity bits to the end of information bits in the encoded codeword, to obtain a permutated encoded codeword; a punching module: according to the length of the signalling, punching the permutated encoded codeword according to a predetermined punching rule to obtain a punched encoded codeword; and a processing and mapping module: conducting second predetermined processing on the punched encoded codeword to obtain a tuple sequence, which is used for mapping, and then mapping the obtained tuple sequence into a signalling symbol according to a predetermined mapping rule.

In addition, an embodiment of the present invention further provides a signalling demodulation and decoding device, characterized in that the device comprises: a demapping module: demapping a receiving end signalling symbol corresponding to a sending end signalling symbol according to a predetermined mapping rule to obtain a log likelihood ratio; a corresponding permutation deprocessing module: conducting corresponding inverse second predetermined processing, inverse punching and inverse permutation on the log likelihood ratio according to the steps of parity bit permutation, punching and second predetermined processing in the signalling coding and modulation device at a sending end to obtain a log likelihood ratio of a receiving end encoded codeword corresponding to a sending end encoded codeword; and a decoding module: conducting corresponding decoding, inverse extension and inverse first predetermined processing on the log likelihood ratio of the receiving end encoded codeword according to the steps of first predetermined processing, extension and predetermined coding in the signalling coding and modulation device at a sending end to obtain signalling.

The signalling coding and modulation device and signalling demodulation and decoding device provided in this embodiment respectively correspond to the signalling coding and modulation method and signalling demodulation and decoding method in the embodiments above, and therefore the structures of and technical factors in the devices may be formed by corresponding conversion of generation methods, and will not be described again herein.

Although the present invention has been disclosed above with preferred embodiments, they do not mean to limit the present invention. Any skilled in the art may utilize the method and technical contents disclosed above to make possible changes and amendments on the technical solutions of the present invention without departing from the spirit and scope of the present invention. Therefore, any content that does not depart from the technical solutions of the present invention, and any simple amendments, equivalent variations and modifications made on the above embodiments according to the technical essence of the present invention all fall within the scope of protection of the technical solutions of the present invention. 

What is claimed is:
 1. A signalling coding and modulation method, of the method comprising: scrambling signalling and conducting BCH coding on the scrambled signalling to obtain BCH parity bits with a length of 168 bits; splicing the BCH parity bits to the end of the scrambled signalling to obtain a BCH codeword; extending the BCH codeword according to an extension pattern table to obtain an extended BCH codeword with a length of 6480 bits; conducting LDPC coding on the extended BCH codeword to generate an LDPC codeword based on a LDPC code with a code rate of 6/15 and a code length of 16200 bits, the LDPC codeword comprises the extended BCH codeword and parity bits; conducting parity bit permutation on the parity bits in the LDPC codeword and splicing the permutated parity bits to the end of the extended BCH codeword in the LDPC codeword to obtain a permutated LDPC codeword; according to a length of the signalling, puncturing the permutated LDPC codeword according to a predetermined puncturing rule to obtain a punctured LDPC codeword; and conducting bit rotation on a tuple sequence obtained by conducting predetermined processing based on the punctured LDPC codeword, and then mapping the rotated tuple sequence into signalling symbols according to 256QAM mapping rule.
 2. The signalling coding and modulation method of claim 1, wherein the step of extending the BCH codeword according to an extension pattern table to obtain an extended BCH codeword with a length of 6480 bits comprises: based on a size of 360 bits of a LDPC codeword sub-block contained in each group, forming the extended BCH codeword with the length of 6480 bits by sequentially splicing 18 groups, the length of the BCH codeword is N_(BCH), if the number N_(Pad) of completely extended groups is greater than zero, i.e., ${N_{Pad} = {\left\lfloor \frac{{6480} - N_{BCH}}{360} \right\rfloor > 0}},$ filling the π(0)th group to the π(N_(Pad)−1)th group in the extended BCH codeword with zeros; if the number N _(Pad) of the remaining extended bits is greater than zero, i.e. N _(Pad)=6480−N_(BCH)−360N_(Pad)>0, then filling the first 6480−N_(BCH)−360N_(Pad) bits of the π(N_(Pad))th group with zeros; and filling bits which have not been filled with zeros of the extended BCH codeword with the BCH codeword from front to back.
 3. The signalling coding and modulation method of claim 2, wherein the π(0)th group, π(1)th group, . . . , π(17)th group in the extended BCH codeword are defined by the extension pattern table, the extension pattern table comprising: Extension pattern table π(0), π(1), . . ., π(17) 15 7 8 11 5 10 16 4 12 3 0 6 9 1 14 17 2 13


4. The signalling coding and modulation method of claim 1, wherein the step of conducting LDPC coding on the extended BCH codeword to generate the LDPC codeword is based on a LDPC code table as below: LDPC code table Row 1: 27 430 519 828 1897 1943 2513 2600 2640 3310 3415 4266 5044 5100 5328 5483 5928 6204 6392 6416 6602 7019 7415 7623 8112 8485 8724 8994 9445 9667 Row 2: 27 174 188 631 1172 1427 1779 2217 2270 2601 2813 3196 3582 3895 3908 3948 4463 4955 5120 5809 5988 6478 6604 7096 7673 7735 7795 8925 9613 9670 Row 3: 27 370 617 852 910 1030 1326 1521 1606 2118 2248 2909 3214 3413 3623 3742 3752 4317 4694 5300 5687 6039 6100 6232 6491 6621 6860 7304 8542 8634 Row 4: 990 1753 7635 8540 Row 5: 933 1415 5666 8745 Row 6: 27 6567 8707 9216 Row 7: 2341 8692 9580 9615 Row 8: 260 1092 5839 6080 Row 9: 352 3750 4847 7726 Row 10: 4610 6580 9506 9597 Row 11: 2512 2974 4814 9348 Row 12: 1461 4021 5060 7009 Row 13: 1796 2883 5553 8306 Row 14: 1249 5422 7057 Row 15: 3965 6968 9422 Row 16: 1498 2931 5092 Row 17: 27 1090 6215 Row 18: 26 4232 6354


5. The signalling coding and modulation method of claim 1, wherein the step of conducting parity bit permutation on the parity bits in the LDPC codeword and splicing the permutated parity bits to the end of the extended BCH codeword in the LDPC codeword to obtain a permutated LDPC codeword comprises: conducting first parity bit permutation on the parity bits to obtain a first permutated parity bits; dividing the first permutated parity bits into several continuous groups and exchanging the positions of the groups so that the π_(p)(k)th group before the exchange becomes the kth group after the exchange to obtain a second permutated parity bits; and sequentially concatenate information bits and the second permutated parity bits to obtain the permutated LDPC codeword.
 6. The signalling coding and modulation method of claim 5, wherein in the step of exchanging the positions of the groups so that the π_(p)(k)th group before the exchange becomes the kth group after the exchange, it is determined according to a predetermined position permutation table: Predetermined position permutation table π_(p)(0), π_(p)(1), . . ., π_(p)(26) 26 5 11 15 6 10 3 9 24 0 4 13 14 19 25 12 7 17 2 16 21 18 1 23 22 8 20


7. The signalling coding and modulation method of claim 1, wherein the predetermined puncturing rule comprising the steps of: calculating a first puncturing number by means of a first puncturing calculation formula according to the length of the signalling; calculating a second puncturing number by means of a second puncturing calculation formula according to the first puncturing number; and removing the second puncturing number of last bits of the permutated LDPC codeword to obtain the punctured LDPC codeword.
 8. The signalling coding and modulation method of claim 7, wherein the first puncturing calculation formula uses: the first puncturing number $N_{punc\_ tem} = \left\lfloor {{\frac{49}{256}\left( {{6480} - K_{sig} - {168}} \right)} + {8246}} \right\rfloor$ wherein K_(sig) is the signalling length.
 9. The signalling coding and modulation method of claim 8, wherein the second puncturing number N_(punc) is calculated by means of the second puncturing calculation formula according to the first puncturing number N_(punc_temp), the second puncturing calculation formula uses: $N_{punc} = {N_{punc\_ temp} - {\left( {{\left\lceil \frac{N_{BCH} + {9720} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil\eta_{mod}} - N_{BCH} - {9720} + N_{punc\_ temp}} \right).}}$
 10. The signalling coding and modulation method of claim 1, wherein the step of obtaining the tuple sequence by conducting predetermined processing based on the punctured LDPC codeword comprises removing zeros added to the punctured LDPC codeword in extension processing, and conducting bit demultiplexing on the LDPC codeword with zeros removed to obtain the tuple sequence.
 11. The signalling coding and modulation method of claim 10, wherein the length of the BCH codeword is defined as N_(BCH), and a first puncturing number calculated according to the predetermined puncturing rule is defined as N_(punc_temp), wherein the step of obtaining the tuple sequence based on the LDPC codeword with zeros removed comprises: successively writing the LDPC codeword with zeros removed into a matrix containing η_(mod) columns and $\left\lceil \frac{N_{BCH} + {9720} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil$ rows according to columns; and sequentially reading out from the matrix by rows, and forming one tuple with η_(mod) bits in each row to obtain the tuple sequence containing $\left\lceil \frac{N_{BCH} + {9720} - N_{punc\_ temp}}{\eta_{mod}} \right\rceil$ tuples.
 12. A signalling demodulation and decoding method, of the method comprising: demapping receiving end signalling symbols corresponding to signalling symbols of claim 1 according to the 256QAM mapping rule to obtain log likelihood ratios corresponding to the tuple sequence after bit rotation conducting corresponding inverse bit rotation, inverse predetermined processing, adding zeros, inverse parity bit permutation, and LDPC decoding on the log likelihood ratios according to the steps of the LDPC coding, the parity bit permutation, the puncturing, the predetermined processing and the bit rotation in the signalling coding and modulation method of claim 1 to obtain a receiving end BCH codeword corresponding to the sending end LDPC codeword; and conducting corresponding zeros removing, BCH decoding and inverse scrambling on the receiving end LDPC codeword according to the steps of scrambling, BCH coding and extension in the signalling coding and modulation method of claim
 1. 